Valve for internal-combustion engines



April 14, 1925.

1,533,782 P. A. E. ARMSTRONG VALVE FOR INTERNAL comausnon mamas Original FiledDe'. 12. 1919' 11v VIENTOR 74/775720 A TTORNE Y Patented Apr. 14, 1925.

UNITED STATES PATENT OFFICE.

PERCY A. E. ARMSTRONG, 0F LOUDONVILLE, NEW YORK, ASSIGNOR T0 LUDLUM STEEL COMPANY, OF WATERVLIET, NEW YORK, A CORPORATION OF NEW JERSEY.

VALVE FOR INTERNAL-COMBUSTION ENGINES.

Original application filed. December 12, 1919, Serial No. 344,294. Divided and. this application filed February 12, 1923.

To all whom it may concern:

Be it known that I, PERCY A. E. Ann- STRONG, a subject of the King of Great Britain, and a resident of and having a postoflice address at Loudonville, county of Albany, and State of New York, have invented a new and-useful Improvement in Valves for Internal-Combustion Engines, of which the following is a specification.

My invention relates to valves for inter nal combustiOn engines, made from alloy steel containing principally iron, chromium, silicon and carbon, and having high surface stability under the conditions to which internal combustion valves are subjected in use;

The present application is a division of my prior copending application Serial No. 344,294, filed Dec. 12, 1919.

The percentages given herein are by weight.

The valves of the present invention are made from alloy steel having over about 5% and under about 13% of silicon and chromium taken together. The silicon content may be from about .5% to about 7% and the chromium content from about 3% to about 10%, the proportions being distributed between chromium and silicon to keep the total of silicon and chromium taken together between about 5% and about 13%. The stable surface qualities of the valves, While fairly good at or toward such lower limits for chromium and silicon taken together, are better at or toward the upper limits stated.

With such proportions of chromium and silicon the carbon should be kept low. Carbon as low as .05% ma be used. .Prefer ably the carbon should kept under onehalf of the silicon, and also under one-tenth of the silicon and chromium taken together.

With valves of alloy steel of compositions at about the lower end of the range referred to, containing silicon 2.5% and chromium 3%, for example, the carbon' should preferably be under about 55%, since with such material further increase of carbon to say 1% results in a considerable re- Serial No. 618,693.

duction in the desired stable'surface stability. Carbon .30%, for example, gives good results in valve making.

One good stable surface alloy valve steel of about the upper end of the range re- -ferred to contains silicon 3.7%, chromium 8.9%, carbon 116%, manganese 23%, sulfur 014%, phosphorus .018%, and the remainder iron.

For maximum rust resisting properties the heat treatment of the valves may be of various sorts, so long as same results in fixing the ground mass of the material substantially solid solution. The preferable heat treatment consists in heating to about 18501900' F., and rapidly cooling. The valves may be cooled in the air or in molten salts, oil, water or other suit-able quenching agent. The drawing temperature for valves may be comparatively high; drawing tom-- peratures up to about 1350" F. give good results.

The steel from which the valves are made, as already stated, may contain small proportions of metalloids, such as sulfur, phosphorus, etc.-, and may also contain variable percentages of metallic elements. If the chromium and silicon content is relatively high, that is to say, in the neighborhood of 13%, the pro-portions of such metallic elements which may be present without sub stantial detriment to the surface stability of the valves, may be correspomlingly increased. It is undesirable ordinarily to have any of these metallic elements in proportions over 1% with the total chromium and silicon used as low as 5%, but with say 13% of chromium. and silicon taken together, metallic elements can be incorporated up to a total of 2-5% without substantial detriment to the properties of the valves, and may be incorporated to serve their usual andwell understood purposes.

Among the metallicelements which may be incorporated are cobalt, nickel, mangan-- ,ese, molybdenum, tungsten, vanadium, titan-' ium, zirconium, and other metals which form silicides or compounds or alloys with the iron or chromium or both, and do not have a material adverse effect upon the fixation of solid solution ground mass by heat treatment.

The alloy steel valves made from the described materials, particularly toward the upper end of the range for chromium'and silicon taken together, are a very superior product having good Wearing qualities and stand up for very long periods without scaling when subjected to the high temperatures in internal combustion engines, thereby obviating the necessity for frequent regrinding. Valve seats for internal ombustion engines may also be made from such material and similar advantages obtained in use.

The accompanying drawing is a side view of an internal combustion engine valve, which comprises the stem 10 ,and head 11 having the seating portion 12 which is adapted to be seated against a valve seat. Reference character "13 indicates the peripheral groove formed in the valve stem and adapted for receiving a collet or the like for the purpose-of taking the spring load.

' As is usual with valves, the tappet end 14 is preferably hardened to resist wear and knocking up. This. may be done by reheating the tappet end of the valve stem to around 1900 degrees F. and rapidly cooling.

I claim: K

1. Valves for internal combustion engines made from alloy steel containing silicon over about -.5% and under about 7%, chromium over about 3% and under about 10%, silicon and chromium taken together over about 5% and under about 13%, carbon over about .05% and under one-tenth the chromium and silicon taken together, and the principal part of the remainder iron.

2. Valves for internal combustion engines made from alloy steel containing chromium' about 310%, I

taken together about 5-13%,

silicon about .57%, chromium and silicon carbon about .051.3%, and the principal part of the remainder iron, said valves being heat treated, the heat treatment including heating to about 18501900 F., and cooling.

3. Valves for internal combustion engines made from alloy steel containing silicon over about .5% and under about 7%, chromium over about 3% and under about 10%, silicon and chromium taken together over about 5% and under about 13%, carbon over about .05% and under one-tenth the chromium and silicon taken together, and also under one-half the silicon, and the principal part of the remainder iron.

4. Valves for internal combustion engines made from alloy steel over 1% and under 4%, and under 9%, 1%, iron.

5. Valves for internal combustion engines containing silicon chromium over 3% carbon over .20% and under and the principal part of the remainder and the maximum of made from allo steel containing silicon over 2% and und and under 5%, carbon under .55%, and the principal part of the remainder iron.

6. Valves for internal combustion engines made from alloy steel containing silicon about 3.7%, chromium about 8.0%, carbon about .46%, and the principal part of the remainder iron.

7. Valves for internal combustion engines made from alloy steel containing chromium about 89%, silicon about 3.54%, carbon about .40-.60%, and the principal part of the remainder iron.

8. Valves for internal combustion engines made from alloy steel containing chromium about 89%, silicon about 35- 1%, carbon about 40-50%, and the principal part of the remainder iron, and having the ground mass fixed, substantially solid solution by he at treatment.

9. As a new article of manufacture, a valve comprising a head and a stem integral therewith made from ferrous alloy containing upon analysis silicon between 1% and 4%, chromium between 3% and 10%, chromium and silicon taken together between 5% and 13%, carbon between 30% and a maximum of one-tenth the sum of silicon and chromium contents, and the principal part of the remainder iron.

10. As a new article of manufacture, a valve comprising a head and a stem integral therewith made from ferrous alloy containing upon analysis silicon between 1% and 4%, chromium between 3% and 10%, chromium and silicon taken together between 5% and 13%, carbon between .30% and a maximum of one=tenth the sum of silicon and chromium contents, about 2-5% of other alloy metals, and substantially all the balance iron.

11. As a'new article of manufacture, an internal combustion engine valve "comprising a head and a stem integral therewith made from ferrous alloy containing upon analysis silicon between .75% and 3.7%, chromium between 5% and 10%, carbon between .30% and the maximum of one-tenth the sum of the silicon and chromium contents, and the principal part of the remainder iron.

12. As a new article of manufacture, an internal combustion engine valve comprising er 4%, chromium over 3%- a head and a stem integral therewith made from ferrous alloy containing upon analysis silicon between .75% and 3.7%, chromium between 5% and 10%, carbon between 30% one-tenth the sum of the silicon and chromium contents, about 2 5% ly all the balance iron.

13. internal combustion engine valve comprisof other alloy metals, and substantial-.

As a new article of manufacture, an

ing a head and a stem integral therewith of the silicon and chromium contents, about made from ferrous alloy containing upon 2-5% of other alloy metals, and substantially analysis silicon between .7 5% and 3.7%, all the balance iron.' 1

chromium between 5% and 10%, chromium In testimony that I'claim the foregoing, 5 and silicon taken together between 5% and I have signed my name hereto.

13%, carbon over 30% and under one-halt the silicon and also under one-tenth the sum PERCY A. E. ARMSTRONG. 

